Fluoride Action Network

Hastings: CDC engineer says costs vary to add fluoride

Source: Hastings Tribune | October 30th, 2008 | By Shay Burk
Location: United States, Nebraska

For many, the cost of fluoridating the city’s water supply has become a concern that may keep them from voting in favor of a health benefit they support.

In May, the Hastings Utilities Board of Public Works was presented with the proposed costs for establishing and maintaining a fluoride treatment program in the city.

There are major cost differences between fluoridating 24 wells and only fluoridating the water through two centralized treatment sites, HU officials said.

At the time, HU manager Marv Schultes said the initial costs for the wellhead treatment program would be $1.1 million, compared to $317,700 if the centralized treatment plants were established.

Without the centralized treatment plants in operation or even in the major planning stages at this point, however, Schultes said if fluoridation is allowed in the city, HU would have to pay the costs to inject fluoride into 24 city wells.

The May estimates reveal the annual cost to supply the 24 wells with fluoride would be $91,700. That would include the annual chemicals, power, transportation, labor and equipment for each of the 24 wells. The estimate also includes the storage of drums at the warehouse.

Those costs would be to inject fluorosilicic acid, a liquid form of fluoride, into the water supply at each of those 24 wells.
Kip Duchon, National Fluoridation Engineer with the Centers for Disease Control, said the costs are different for each community, based on a number of factors including the type of fluoride additive that is used. The three approved types of fluoride additives allowed in the United States are sodium fluoride, sodium fluorosilicate and fluorosilicic acid.

“Nationwide, you can expect to spend somewhere on the order of as little as $3 per person in the community to up to $20 per person, but that depends on so many different factors,” he said.

While he has done no calculations of his own, Duchon said based on what he knows of Hastings and its water system, he would expect the costs here to be in the mid-range.

The largest costs of fluoridation will be the initial setup and constructions costs, he said.

“Once you’ve got the facilities built, the operation costs are pretty low all the way around,” he said. “The important thing to remember is nationwide, the cost to provide fluoridation to a person for his or her entire lifetime is less than the cost of one cavity.”

The differences between communities with fluoridated water and those without is significant, Duchon said.

“The research shows if you have lived in a fluoridated community your entire life you will have 40 percent fewer cavities than someone who has not lived in a fluoridated community,” he said. “That’s a big difference.”

When it comes to the actual implementation of a fluoridation program, Duchon said the steps and the cost can be different based on the type of fluoride used.

He said there is no way for a community to really know which additive will be the easiest or most cost-effective based on their system until it is in place.

“Each system is unique,” Duchon said.

With smaller water systems, he said using sodium fluoride, a dry additive, in a saturator is going to be the least expensive alternative. In the same sense, he said larger communities often find fluorosilicic acid to be the most cost-effective way of adding fluoride. Sodium fluorosilicate oftentimes is the middle ground between the other two for medium-sized communities.

Duchon said that is only a theory and doesn’t always work in practice.

“In Hastings, I understand you have a relatively high hardness water, which tends to not favor sodium fluoride in saturators,” he said.

The hardness of the water makes it more difficult for the sodium fluoride to dissolve. In that case, Duchon said sodium fluorosilicate or fluorosilicic acid is a better option.

“You have to look at each individual installation and make the determination as to what makes the most sense,” he said.
One of the cost issues related to the installation is the difference in the equipment needed.

With the two dry forms of fluoride, a chemical dry feeder is needed to put the fluoride into a saturator to dissolve the fluoride before it is put into the water supply.

“The acid is the simplest, equipment-wise, because all you really need is a tank and a pump,” Duchon said.

This highly precisioned chemical feed pump is used to make sure the precise level of fluoride is put into the water.
There are a variety of different types of pumps so the engineer designing the system has the option to choose the pump that can only put in an amount of fluoride in a specific range as to not allow more than needed to be put in at any given time.

As a way to make sure a larger amount than recommended isn’t put into the water, Duchon said there are CDC guidelines and 10 State Standards that establish requirements for the design of fluoridation systems.

With the injection of fluorosilicic acid, he said there is a bulk storage tank that holds a long-term supply of the acid. At each injection site there is a smaller storage tank that should only hold about as much as is needed for one day.
This ensures that if the pump should ever fail, no more than a day’s worth of fluoride would go into the water.

“If the facilities are designed in accordance with 10 State Standards, which I think they have to be for your state, then you’re going to have the ultimate backup of a day tank,” he said.

No matter what system is used, Duchon said engineers have been working with water fluoridation systems since the 1940s and know what they’re doing.

“Over that time period, we have learned what things we have to do from an engineering perspective to achieve the results that are important to protect the public,” he said. “That’s to ensure the public has good oral health, but also doesn’t have exposure to excessive fluoride.”